After you installed your OS, under Device Manager are listed “Unknown Device.” So how to identify the devices?

According to Annoyances, ” This means that Windows has detected a device for which it has no driver. Go over the other devices in your system, see if you have any hardware that isn’t listed, and then contact the manufacturer of the missing devices for the appropriate drivers. Note that sometimes the Device Manager lists devices that either don’t exist or exist but don’t need drivers.”

Well there are a few options here, namely

Open up your CPU unit, try to identify the device yourself and download the necessary driver, or